Dakota Group

Upper part is white, light-gray, brownish-gray, yellow, redish-brown, and red sandstone and shale. Sandstone is very fine to coarse grained, friable, micaeous, crossbedded, and lenticular; locally contains gravel near base. contains numerous zones of ironstone and siltstone concretions of variable thickness. Middle part is light-gray, yellow, red brown and dark-gray, sandy carbonaceous shale; commonly contains a zone of concretions near top. Lower part is sandstone similar to that in upper except there are zones of siderite concretions and, locally a basal zone of chert pebbles. Approx. max thickness 600 ft.
State Nebraska
Name Dakota Group
Geologic age Early Cretaceous
Lithologic constituents
Sedimentary > Clastic > Mudstone > Shale (Bed)
Sedimentary > Clastic > Sandstone (Bed)
Unconsolidated > Coarse-detrital > Gravel (Bed)
Comments Divided into Upper, Middle, and Lower. Deposited in nonmarine and shallow-marine enviroments.
NGMDB product
Counties Burt - Butler - Cass - Cedar - Colfax - Cuming - Dakota - Dixon - Dodge - Douglas - Fillmore - Gage - Jefferson - Lancaster - Otoe - Saline - Sarpy - Saunders - Seward - Thayer - Thurston - Washington - York